LaTeX.org

I would use such tex-assembler to manage lesson notes and pick up exercises for students.
I would be able to provide tailored notes to students, at different stages of the math class, showing a given number of exercises, skipping theoretical details, theorem demonstrations, etc. and adding examples ...

As latex adoption is spreading well over preparation of research articles,
re-usability might become a wanted feature.
I would like to know of any developers with plans on this regard.

Here is my naive idea: an application to
1) break up a tex document into sections and subsections, each of them ...